CUMBERLAND County Average 2005 NATA Modeled Air Concentrations Compared to Health Benchmarks

Pollutant

Modeled
Air Concentration (ug/m3)

Health
Benchmark (ug/m3)

Risk
Ratio

%
Contribution from

Point Sources

Nonpoint
Sources

On-road
Mobile Sources

Nonroad
Mobile Sources

Background & Secondary

Acetaldehyde

1.5

0.45

3.4

<1%

1%

1%

1%

97%*

Acrolein

0.026

0.020

1.3

<1%

20%

5%

6%

69%*

Arsenic Compounds

0.00040

0.00023

1.7

1%

7%

1%

1%

90%

Benzene

0.68

0.13

5.3

<1%

7%

9%

5%

79%

1,3-Butadiene

0.048

0.033

1.5

<1%

<1%

12%

6%

82%

Cadmium Compounds

0.000067

0.00024

0.3

2%

33%

0%

<1%

65%

Carbon Tetrachloride

0.61

0.067

9.1

0%

<1%

0%

0%

100%

Chloroform

0.071

0.043

1.6

<1%

17%

0%

0%

83%

Chromium (hexavalent form)

0.00012

0.000083

1.5

17%

4%

1%

<1%

78%

Cobalt Compounds

0.00016

0.00011

1.4

100%

0%

0%

0%

0%

1,4-Dichlorobenzene

0.072

0.091

0.8

<1%

36%

0%

0%

64%

1,3-Dichloropropene

0.047

0.25

0.2

0%

100%

0%

0%

0%

Diesel Particulate Matter

0.19

0.0033

57

0%

0%

42%

58%

0%

Ethylbenzene

0.048

0.4

0.1

3%

20%

44%

33%

0%

Ethylene Oxide

0.0072

0.011

0.6

3%

11%

0%

0%

86%

Formaldehyde

1.6

0.077

21

<1%

2%

2%

1%

95%*

Methyl Chloride

1.2

0.56

2.1

<1%

<1%

0%

0%

100%

Naphthalene

0.041

0.029

1.4

1%

44%

11%

3%

41%

Nickel Compounds

0.00024

0.0021

0.1

26%

26%

2%

6%

40%

PAH/POM

0.0067

0.0072**

0.9

2%

91%

2%

5%

0%

Perchloroethylene

0.10

0.17

0.6

<1%

38%

0%

0%

62%

1,1,2-Trichloroethane

0.019

0.063

0.3

0%

100%

0%

0%

0%

Chemicals with risk ratios greater than or equal to 1 are
in bold.
Risk Ratios based on noncarcinogenic effects are in italics.
The symbol ug/m3 is micrograms per cubic meter,
the amount (in micrograms) of a chemical in a cubic
meter of air. This is also known as a concentration.
For diesel particulate matter, onroad and nonroad
concentrations include a model-estimated background
concentration. *Acetaldehyde, acrolein and formaldehyde concentration estimates include secondary formation, which is the process by which chemicals in the air are transformed into other chemicals.**PAH/POM is "polycyclic aromatic hydrocarbons/polycyclic organic matter." These define a broad class of compounds. The chemicals making up this class were broken up into 8 groups based on toxicity, and each group was assigned a cancer-weighted toxicity estimate. 0.0072 ug/m3 is the health benchmark average across the 8 groups.